Is your rating is below 2200 and did you learn your chess outside the Soviet Union?
Then we advise you to take a look at Artur Jussupow's
Build Up Your Chess 2.
This is a methodical course of progressively difficult training material: not pages of instructional prose,
but a graded workbook.
Jussupow mixes chapters on subjects like calculation, endings, tactics, openings etc. A very short introduction is followed by a series of examples, and rounded off by a dozen of tests.Some of the material may LOOK familiar, but Jussupow's method will probably lead you to discover many fundamental gaps in your knowledge.
Very good training stuff for less advanced players, chess coaches and players who want to repare weaknesses in their play.